﻿#include<iostream>
using namespace std;
class Time
{
public:
	Time(int hour)
		:_hour(hour)
	{
		cout << "Time()" << endl;
	}
private:
	int _hour;
};

class Date
{
public:
	Date(int& x, int year = 1, int month = 1, int day = 1)
		: _t(12)
		, _ref(x)
		, _n(1)
	{
		
	}
private:
	int _year=2024;
	int _month=5;
	int _day=18;
	Time _t;
	// 没有默认构造
	int& _ref;
	// 引⽤
	const int _n; // const
	
};
int main()
{
	int i = 0;
	Date d1(i);
	
	return 0;
}